Ironically, most of California does not have the cleanest water. The summers are dry, and the last decade has seen a decline year after year. I think this year was up from recent, but still below what is considered average. If you look at the link you'd see that many of the cities with the highest levels are located in California. As the (now 6th) largest economy in the world the amount of manufacturing and processing that goes into the fertilizers and pesticides in the central valley used to grow vegetables and fruits, the chemical processes of turning out a good majority of electronics, and the overall attitude of Californians to TRASH the state has really polluted just about everything there.
I assure you, there is no other State that from top to bottom is covered in trash like California is. If you live there, check this out, while you drive along the road, freeways are best, count the items of trash located on the side of the road. You won't believe it. I didn't even notice it myself until I took the train to Colorado (got off in Fraser). The entire way through cali, staring out the window, it was just garbage, couches, homeless shelters, more garbage, half a rusted car... Fucking nasty. But the moment we hit Nevada it was CLEAN the whole way! I spent some time in Arizona looking for the trash. Even up here in Oregon, despite being full of Californian transplants, it is still cleaner.
Northern California, and the coastal range valley cities, get enough fresh water to save some of it for the dry season. Where I grew up near Santa Cruz we had a lot of ground water and a big river so I never needed reclaimed water. Southern Cal is really a desert that they turned into cities. There's a reason the colorado river doesn't reach the ocean anymore. The run off from all this stuff just accumulates over time. The recycling process isn't nearly good enough to remove what they should be (obviously).
My girlfriends uncle actually started his own business installing serious in home water filtration systems. Recirculating RO systems, rain catchers, and shit like that. He does very well for himself in the North Bay.
I moved North from the Bay Area to Oregon. I lived in Colorado, all over California, been all across the country, and I fracking LOVE it here. The water, the air, the food, the people, just the vibe and energy. It was like when I got here I finally felt at "home." When I go back to California, I say "Going-going back, back to, Cali, Cali" And when I leave I say "I'm going back home. To Oregon."
One day I'd love to move to Napa or Sonoma back in California. Maybe if they legalize it. I have family friends that own a winery in Paso Robles and would love to get into doing what they do plus cannabis.
I think the message here, to stay on topic somewhat, is that you cannot just trust your water. There are people out here who get 55ppm straight from the tap. If you are pulling in 300-400ppm and it isn't well/ground water, then you've got a huge variety of contaminants in your tap. Asprin, Birth Control, Laundry soap, Paper processing chemicals, and heavy metals. Sure, you might be the ONE lucky person who lives in a city that treats their water properly but it just happens to have a lot of minerals... But if you happen to have more than 25,000 in your town and your own water reclamation plants... fuck drinking that piss!
Brita filters are pretty cheap and do a good enough job to make your tap water passable.
Now think about that. How much would it cost the water company to just filter the fucking water Brita style? Sure, probably a little bit... but they are so cheap about it they figure you can filter it yourself, and I think you should.